Internally, there are various action names. You will never see them unless you look at the XML output. They are used to organise the way that various keys behave in different dead key states, and hand-crafted keyboard layouts generally name the actions after the output with no dead key active.

If you want to change an action name, you can do so by choosing “Change Action Name...” from the Keyboard menu. After you select an action name, you can enter a new name. The only restriction is that you cannot use a name that already exists.